One of the ways that you can overcome the 508 character limit for bookmarklets in IE 6 is to use a local bookmarklet stub that references a server side javascript file. See:Better Living Through Bookmarklets [JavaScript & DHTML Tutorials]

The problem is that IE's security model blocks document.write unless it writes into a new page, which is a problem if people have popup blockers.

Does anyone know of a workaround? (Sorry, I have comments blocked cos of spam, so email is the only option to reply).